"Bald Eagle" <cre### [at] netscapenet> wrote:
> William F Pokorny <ano### [at] anonymousorg> wrote:
>
> > Got up to go to the bathroom(*) and, wow, a lot of posts in this thread.
>
> > Lastly, you could play with higher adc_bailout values too as a solution
> > to the v3.7 rendering.
>
> I thought this was just straight rendering - no radiosity.
>
> Also, I replaced all of the ambient statements with emission.
>
> > On your particular question about artifacts. The discs at larger radius
> > values will start to cross each other. Where they do there will be a
> > seam of numerical instability somewhat like coincident surfaces. Some
> > likelihood this is the cause of the artefacts, but unsure how to be sure
> > at moment. Can you filter out some range of discs closer to the camera
> > location?
>
> I would think the lines would be curved in that instance?
>
> Just out of curiosity, I was wondering what the actual overall scene looked
> like, so once I wrapped my head around the coordinate system and
> camera-to-look_at orientation, I was able to pull the camera back and look down
> over the entire undistorted market.
> (see attached)
>
> There are places where there are significant holes / spaces.
> I'm wondering if perhaps part of the problem may be that the lines are places
> where the rays are making it through to the black background.
>
> Perhaps a non-zero (1/255) sky_sphere or background may help, or something like
> a fog effect where the foreground is crystal clear, but the far-away spaces get
> filled in with a lighter color.  Maybe some sort of large box with a gradient
> that's the 4th root of the normalized total distance... that sort of thing.
>
> Due to the time difference, I'm _just_ getting up and having First Coffee - so,
> you're getting what you're paying for.  ;)
>
> - BW
>
> A huge point set like this is a real treat to play with, since it is large,
> asymmetric, offers human-recognizable structure, and has color data built in.
> I've been wanting to do a 3D convex hull algorithm, and this would be a great
> final test for that.
> Wondering what would happen if instead of discs or cylinders or spheres, _cones_
> were used instead, oriented looking straight at the smaller face and the larger
> end being just large enough to protrude: maybe that might fix the dark artifact
> lines if it's a see-through effect.

"A huge point set" .... I need to tell you that the sample I put on line for
testing is about 1/100 of the points in the actual scan. :-)

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